Posts in category

Week 26


Special Topic: Orbits and Future Returns

Read More

JUNE 22, 1978: U.S. Naval Observatory astronomer James Christy discovers Charon, Pluto’s first-known moon. Charon, the discovery of which would be confirmed with a series of transit and occultation events between it and Pluto that began in 1995, provided a major step in our understanding of Pluto’s size and physical nature. Pluto, its system of …

Perihelion: 2020 June 25.85, q = 0.337 AU  In the early 19th Century the idea that comets might return to the inner solar system on a regular basis was still a bit of a novelty. This had been successfully demonstrated by the British astronomer Edmond Halley when the comet that now bears his name returned …

“Ice and Stone 2020” participants have undoubtedly noticed that I have often discussed how this-or-that comet or asteroid will be returning to the inner solar system or passing by Earth at some point in the future, and perhaps have wondered how such things are determined. In principle, the processes by which such events are calculated …